JPS5946429B2 - Method for manufacturing a light emitting display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a light emitting display device, and particularly to a light emitting display device having an improved method for assembling light emitting element pellets in a light emitting display device forming a numerical display, a matrix display, etc. Regarding the manufacturing method.

In manufacturing a conventional light-emitting display device that displays numbers, a light-emitting element wafer is first adhered to a spreadable adhesive sheet and diced using a blade dicer or the like, as shown in the top view in FIG.

That is, in the figure, 1 is a light emitting element wafer, 2 is an adhesive sheet, and 3 is a dicing line provided on the wafer. Next, after applying breaking and dividing into individual pellets, the crushed layer caused by this dicing was removed to improve the external quantum efficiency, and the surface electrode was cleaned.
For the purpose of performing good wire bonding, the pellets were broken up into pieces and the pellets 1a, Ia', . . . were placed in the etching solution 4 as shown in FIG.
The etching process is performed by immersing the The light-emitting element pellets obtained as described above are a mixture of luminances that differ depending on each part within the wafer, so the numerical display of a part of the light-emitting element pellets shown in the front view in FIG. The seven segments that make up the character shape vary in brightness.

That is, in the case where the brightness of a segment is indicated by the density of diagonal lines applied to the segment (no diagonal lines are the brightest, and the denser the diagonal lines are, the darker), the brightest segments 5a and 5f are adjacent to the darkest segment 5b. This may occur in some cases, resulting in a significant deterioration of product quality. Therefore, the pellets found to have uneven brightness were removed from the segments.
One method is to replace the pellets with pellets of the same brightness level, but this requires a great deal of effort and has the disadvantage of causing accidents such as damage to segments, wiring bodies, etc. There is also a significant impediment to the automation of the pellet loading process. The present invention provides a method for manufacturing a light emitting display device that overcomes the above-mentioned conventional drawbacks.

The method for manufacturing a light emitting display device according to the present invention involves dividing and etching a light emitting element wafer while it is adhered to a spreadable adhesive sheet, and then dividing the divided individual light emitting element pellets into rows and It is characterized in that the extensible sheets are assembled directly to the display section in the order of adjoining columns.

Next, one embodiment of the present invention will be explained in detail with reference to the drawings.

FIG. 4 shows a light emitting device wafer 1 (hereinafter referred to as device wafer) bonded to a malleable adhesive sheet 2 and then diced (
A perspective view shows a state in which a dicing line (indicated by 3) has been applied. Next, after applying braking, the sheet is heated and expanded to separate the element pellets 1a, 1a/... as shown in cross section in FIG. While the sheet is supported by the force setting ring 6, the element pellets are etched. Incorporation into the display section of the element pellet is accomplished using a manufacturing apparatus whose operation and part of the mechanism are shown in FIGS. 6 to 11.

This will be explained below using figures. First, the element pellets 1a of the force setting ring 6 are aligned using an optical system (not shown) (FIG. 6). In addition, 7 in the figure is a display part,
7a is a conductive adhesive, 8 is a push needle, and 9 is a back spring. Next, the backup spring 9 moves downward as shown by the broken line arrow in the figure, as shown in FIG. FIG. 7 shows a state in which the back-up spring pushes down the adhesive sheet and brings the element pellet 1a close to or in contact with the conductive adhesive 7a. Then, as shown in FIG. 8, the push unit needle 8 descends and releases the element pellet 1 through the adhesive sheet.
A is pressed onto the conductive adhesive 7a of the display section 7 to adhere it. In Figure 9, the back up spring goes up, and then the push unit needle goes up as well. When the back up spring rises, the seat returns to its original position by the amount of pressure from the back up spring. 1a5 in the figure are element pellets in different rows. Then, as shown in FIG. 10, the push unit needle 8 and back-up spring 9 are also raised and returned to their positions, and the force setting ring 6 and display section 7 are moved. Then, as shown in FIG. 11, the element pellet 1a' adjacent to the element pellet on the adhesive sheet is aligned. Reference numeral 7' denotes a display section on which the element pellet has not yet been assembled, or a display section or segment adjacent to the display section. Then, the mounting of the element pellets is repeated in accordance with the process sequence shown in FIGS. 6 and subsequent figures.
In the above, positioning, displacement, operation, etc. of each part are performed in accordance with commands from a computer (not shown) provided with an optical system device. Next, a method for selecting element pellets on the adhesive sheet for assembling the element pellets into a display section is illustrated in FIGS. 12 to 14.

In the example shown in Figure 12, samples are taken and assembled along the rows,
At the end of a line, the process moves to an adjacent line and the sampling proceeds in the opposite direction to the above line, which is called near-line matching. Arrows and dashed lines in the figure indicate the direction of progress of collection. Next, the example shown in Fig. 13 is similar to the one shown in Fig. 12, but the end of the row is set at the element pellet approximately on the diameter of the wafer, and the sample is then moved to the adjacent row and sampled in the opposite direction to the above row. Advances and is repeated thereafter (prots matching). Furthermore, in the example shown in FIG. 14, the initial element pellet is set at the center of the wafer, and starting from this element pellet, the element pellets surrounding this element pellet are visited and collected, and the collection is successively progressed outward in a spiral shape. This method, together with the method shown in FIG. 13, is called near-plane matching. Note that the selection contents, order, etc. are executed by commands issued from a part stored in advance in the microcomputer of the apparatus. In each of the above-mentioned figures, the division of the wafer is for explaining the collection of element pellets, and is significantly different from the actual division. In other words, one element pellet is 0.3m7! t
It is a cube with corners, and even if 30 to 40 element pellets are used in a light emitting display device, the pellets will span 9 to 12 mm on the wafer. Although there are some variations in the brightness characteristics within the wafer, the brightness characteristics within the wafer are 107 nm. It is completely unacceptable to any extent. Furthermore, since one unit of the ``h'' shape is formed by seven element pellets, the wafer's length is about 2m7n.
In the range of , all segments are recognized to have uniform brightness. According to this invention, since the light emitting element pellets are assembled directly from the extensible sheet to the display part in the order of adjacent rows or columns, the light emitting display device with good quality can be manufactured at high speed without any variation in brightness in each display part. There are significant advantages that can be obtained at

In addition, we can efficiently handle everything from processing element pellets to assembly.
And can be processed and handled uniformly. The device according to the present invention also has the advantage of improving luminance characteristic efficiency by 20 to 30%.

[Brief explanation of the drawing]

FIG. 1 is a front view of a wafer for a light emitting display device during the processing process, FIG. 2 is a sectional view for explaining the etching of a conventional light emitting element pellet, FIG. 3 is a front view of a conventional light emitting display device, and FIG. The figures and subsequent figures show a method for manufacturing a light emitting display device according to an embodiment of the present invention, with FIG. 4 being a front view showing a state where a wafer has been diced, FIG. 5 being a cross-sectional view after braking, and FIGS. FIG. 11 is a sectional view illustrating the steps of collecting and assembling element pellets, and each of FIGS. 12 to 14 is a front view showing the method of collecting element pellets of the present invention. Note that the same reference numerals in the drawings indicate the same or corresponding parts. 1...Light emitting element wafers 1a, 1a'...
・Light emitting element pellet, 2...Adhesive sheet, 5a
...5f...Segment, 6...Force settling, 7...Display section, 7a...
・Conductive adhesive, 8... Push unit needle, 9
・・・・・・Backlash Spring.

Claims (1)

[Claims] 1 Assemble multiple light-emitting element pellets on a board to display numbers,
In the manufacture of light emitting display devices such as matrix displays, the light emitting element wafer is divided and etched while it is adhered to a spreadable sheet, and then the individual light emitting element pellets are separated in the row or column direction. 1. A method for manufacturing a light emitting display device, which comprises assembling the extensible sheets directly onto the display part in the order in which they are adjacent to each other.